DESCRIPTION (Verbatim from the Applicant's Abstract): The long term goal of this research is the development of a plasmid DNA delivery alternative that will increase the effectiveness of gene therapy with plasmids. In the past, the combination of electric pulses with a nonpermeant drug such as bleomycin, eletrochemotherapy, has been an effective localized treatment for various cancers. The success of this technique may be due to increased drug uptake which is directly related to the physiological effects of the electric field (increased membrane permeability). Since electroporation has shown promise as a delivery method for hydrophilic drugs, it should also effectively deliver DNA in vivo. It is important to establish electrical parameters which can maximize DNA delivery and consequent gene expression, as well as to establish a highly reproducible technique. This will be determined by completing the following specific aims: i) to establish the range of electrical field strength and pulse width that will yield maximum expression of genes delivered in vivo directly to the skin; ii) to establish the plasmid concentration that will yield maximum expression of genes delivered in vivo directly to the skin; iii) to determine the time that maximal expression levels can be maintained and if this time can be increased by performing multiple delivery procedures. The work will be performed using C57B1/6 mice The first set of experiments will determine the electric field doses that generate maximal DNA delivery, as measured by reporter gene expression, to skin. One these electrical parameters are established, a plasmid DNA concentration gradient will be performed to determine the DNA concentration for maximal expression. Finally, repeated treatments to maintain long term gene expression will be explored. With this information, in vivo electroporation will be an effective method for plasmid DNA delivery.